59. Given the following SAS program:

proc sql;

select name, salary, birthdate

from employee

where 500 = (select amount from sales where employee.name = sales.name);

quit;

Which SQL procedure program produces the same output?

A. proc sql;

select sales.name, salary, birthdate

from employee, sales

where employee.name = sales.name and amount = 500; quit;

B. proc sql;

select name, salary, birthdate

from employee

where select amount from sales

where employee.name = sales.name = 500;

quit;

C. proc sql;

select name, salary, birthdate

from employee, sales

where name = name and amount = 500;

quit;

D. proc sql;

select (select sales.name from sales where amount = 500), salary, birthdate

from employee

where employee.name = sales.name;

quit;

我想问问为什么不能选D。我用SAS跑了一下程序得到提示“ERROR: Unresolved reference to table/correlation name sales.
”，可是不知到为什么不行。

谢谢~~